Lower specificity of occult-blood test on stool collected by digital rectal examination
Zhang, B.; Nakama, H.; Fattah, A.S.M.Abdul.; Kamijo, N.
Hepato-Gastroenterology 49(43): 165-167
2002
ISSN/ISBN: 0172-6390 PMID: 11949640 Document Number: 543480
Background/Aims: To compare the diagnostic accuracy of an immunochemical fecal occult-blood test for colorectal cancer between the stool specimens obtained during the routine screening and those during the digital rectal examination. Methodology: One hundred and fourteen patients with colorectal cancer and 228 healthy controls served as subjects of the study. Fecal occult-blood was tested by both of two methods; by the routine screening and by the digital rectal examination, and the sensitivity and specificity of an immunochemical fecal occult-blood test were determined in these two methods. Results: The sensitivity and specificity were 79.8% and 96.5% in the routine screening method, and 86.0% and 79.8% in the digital rectal examination method, respectively, showing a significant difference in the specificity (P<0.01) between these two stool collection methods. There was no significant difference in the sensitivity between these two stool collection methods. Conclusions: These findings indicate that the stool specimens collected at the time of the digital rectal examination is not suitable for testing of fecal occult-blood.